Many analytical instruments, such as ion mobility spectrometers (IMS), can require a gating device for turning on and off a flowing stream of ions and/or other charged particles. IMS are widely used in field chemical analysis. IMS separate ionic species based on their ion mobility in a given media (either gas or liquid). Recent development of the IMS technology results in two forms of IMS instruments and systems. The time-of-flight (TOF) IMS separate ions based on their steady state ion mobilities under constant electric field. High resolving power with IMS has been achieved with the TOF-IMS instruments. Alternatively, devices that separate ions based their mobility changes under high field conditions, such as field asymmetric ion mobility spectrometer (FAIMS) or differential mobility spectrometer (DMS), can also be used.
Even though the gating device is a minor component in the overall design of an IMS, if manufactured correctly, this component can improve the IMS resolution and system performance. The gating device is used to regulate the injection of ion packets into the analytical instrument. There are many deficiencies with the current approaches for manufacturing gating devices.
Traditionally the gating device has been used to regulate the injection of ion packets into the analytical instrument. Even though the gating device is a minor component in the overall design of an IMS, this device is an important part that can improve the level resolution between peaks in the IMS by providing a compact ion packet without significant diffusion. Many inventions have been proposed around the manufacturing and designing the gating device for improving the resolution without major improvements. The present invention modifies the gating device in a manner that improves peak resolution and is able to control which size ions are injected into the analytical instrument. This novel gating device significantly reduces the analysis of complex samples with multiple components such that lower mobility ions are not able to enter the drift tube.